/**************************************************************************
 *
 * Copyright 2008 VMware, Inc.
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
 * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 **************************************************************************/

#include "bitscan.h"

#ifdef HAVE___BUILTIN_FFS
#elif defined(_MSC_VER) && (_M_IX86 || _M_ARM || _M_AMD64 || _M_IA64)
#else
int ffs(int i) {
    int bit = 0;
    if (!i)
        return bit;
    if (!(i & 0xffff)) {
        bit += 16;
        i >>= 16;
    }
    if (!(i & 0xff)) {
        bit += 8;
        i >>= 8;
    }
    if (!(i & 0xf)) {
        bit += 4;
        i >>= 4;
    }
    if (!(i & 0x3)) {
        bit += 2;
        i >>= 2;
    }
    if (!(i & 0x1))
        bit += 1;
    return bit + 1;
}
#endif

#ifdef HAVE___BUILTIN_FFSLL
#elif defined(_MSC_VER) && (_M_AMD64 || _M_ARM64 || _M_IA64)
#else
int ffsll(long long int val) {
    int bit;

    bit = ffs((unsigned) (val & 0xffffffff));
    if (bit != 0)
        return bit;

    bit = ffs((unsigned) (val >> 32));
    if (bit != 0)
        return 32 + bit;

    return 0;
}
#endif
